The undercooling at the Si(1 1 1) facet is of great importance, e.g. in explaining effects during grain growth of multicrystalline Si. Data of experiments spread over a wide range and there is only one paper published on numerical simulations (by Beatty and Jackson). However, there are some discrepancies in this paper, which are discussed here. (C) 2011 Elsevier B.V. All rights reserved.